Maybe you can install a bot system who annonce every hours a link to the Tou:
System annoucement : All subscribed players on Nostalrius must keep these rules in mind while playing : viewtopic.php?f=2&t=8
or
Armilus wrote:I don't think it would be a big deal as long as it's not too often.
Instead of just a link to the ToS, you could have a few different messages that are randomly picked from or announced in rotation.
Things like:
"Using any form of Bot is against the terms of service and will result in a permanent ban."
"Buying or selling gold is against the terms of service and will result in a permanent ban."
etc.
.